Crate stacker



N. J. SIMPKINS June 5, 1962 CRATE STACKER 5 Sheets-Sheet 1 Filed Dec.51, 1958 INVENTOR flfqlzfimzz J fill/Fm) BY ATTORNEYS N. J. SIMPKINSJune 5, 1962 CRATE STACKEIR 5 Sheets-Sheet 5 Filed Dec. 51, 1958INVENTOR 17197256912712 J Ji ly/[M47 5% w L Q Q x BY ATTORNEYS N. J.SIMPKINS June 5, 1962 CRATE STACKER 5 Sheets-Sheet 5 Filed Dec. 51, 1958INVENTOR ATTORNEYS United States atent 3,037,645 CRATE STACKER NathanielJeptha Simpkins, Atlanta, Ga., assignor to Miss Georgia Dairies, Inc.,Atlanta, Ga. Filed Dec. 31, 1958, Ser. No. 784,295 6 Claims. (Cl. 214-6)The present invention relates to crate stackers and particularly tocrate stackers which are adapted to automatically stack crates receivedfrom a conveyor and discharge the stacked crates on to the sameconveyor.

Another object of the present invention is to provide a crate stacker ofthe class described above which is actuated by a pneumatic cylindercontrolled by the flow of crates to the stacker.

A further object of the invention is to provide a crate stacker of theclass described above having oppositely disposed lifting membersmaintained in balanced relation by a hydraulic interconnecting means.

Another object of the invention is to provide a crate stackerconstructed in accordance with the invention and having a plurality ofpneumatic control valves actuated by movement of the crates into thestacker and movement of the stacker in its stacking operation.

A further object of the invention is to provide a crate stacker of theclass described above which is combined with a conventional crate movingchain conveyor to move the crates into the stacker individually and tomove the stacked crates out of the stacker upon completion of thestacking operation.

A still further object of the invention is to provide a crate stacker ofthe class described above which is inexpensive to manufacture, positivein its action and which automatically stacks the crates with a minimumof personal attention from the operator.

Other objects and advantages will become apparent in the followingspecification when considered in light of the attached drawings, inwhich:

FIGURE 1 is a perspective view of the invention showing crates beingstacked therein;

FIGURE 2 is a side elevation of the invention;

FIGURE 3 is a front elevation of the invention shown partially brokenaway and in section for convenience of illustration;

FIGURE 4 is a top plan view of the invention;

FIGURE 5 is a horizontal section taken along the line 55 of FIGURE 1,looking in the direction of the arrows;

FIGURE 6 is a fragmentary elevational view of one of the crate liftingcarriages;

FIGURE 7 is a horizontal section taken along the line 7-7 of FIGURE 6,looking in the direction of the arrows;

FIGURE 8 is a perspective view of one of the connecting links;

FIGURE 9 is a horizontal sectional view similar to FIGURE 5 with thecrate removed, illustrating the stop and conveyor chain relationship tothe stacker;

FIGURE 10 is a fragmentary vertical sectional view taken along the line10-40 of FIGURE 9, looking in the direction of the arrows;

FIGURE 11 is a transverse vertical section taken along the line 1i1--11of FIGURE 9, looking in the direction of the arrows;

FIGURE 12 is a fragmentary perspective view of the crate stop releaseshaft;

FIGURE 13 is a longitudinal sectional view of the pneumatic cylindercontrol valve;

FIGURE 14 is a longitudinal sectional view of one of the pilot controlvalves;

FIGURE 15 is a fragmentary perspective view of the hydraulic equalizingcylinders and the connections extending therebetween; and

FIGURE 16 is a semi-diagrammatic view of the pneumatic circuits used inthe device.

Referring now the the drawings in detail wherein like referencecharacters indicate like parts throughout the several figures, thereference numeral 20 indicates generally a crate stacker constructed inaccordance with the invention.

The crate stacker 20 includes a pair of spaced apart parallel uprightangle iron frame members 21, 22 and a second pair of spaced apartparallel upright frame members 23, 24 with the second pair of framemembers 23, 24 arranged in spaced parallel relation to the first pair offrame members 21, 22. A horizontal angle iron frame member 25 connectsthe upper ends of the frame members 2d, 22. A horizontal frame member 26connects the upper ends of the frame members 23, 24. The horizontalframe members 25, 26 are arranged in spaced apart parallel relation andhave their opposite ends connected by spaced apart lateral frame members27, 28. The horizontal frame members 25, 26 are further connected byclosely spaced parallel lateral frame members 27a, 28a, which arepositioned intermediate the frame members 27, 28.

A transverse bar 29 extends between and is welded to the frame members21, 22 intermediate the upper and lower ends thereof. The bar 29 extendshorizontally and is arranged on the side of the frame members 21, 22toward the frame members 23, 24. A horizontal bar 30 is secured to theframe members 23, 24 intermediate the upper and lower ends thereof andon the side thereof toward the frame members 21 22. The bars 29, 30 arearranged in the same horizontal plane. A horizontally extending bar 31extends between and connects the lower ends of the frame members 21, 22underlying the bar 29 and another horizontally extending bar 32 extendsbetween and connects the frame members 23, 24 underlying the bar 30.

A pair of spaced apart parallel cylindrical guide rails 33, 34 arearranged in upright relation and have their respective upper and lowerends secured to the bars 29, 31. A second pair of upright spaced apartparallel guide rails 35, 36 have their respective upper and lower endssupported in the bars 30, 32. A pair of generally rectangular guideblocks 37, 38 are slidably supported respectively on the guide rails 33,34 and are connected together by a horizontally extending shaft 39. Asecond pair of generally rectangular guide blocks 40, 41 are similarlysupported on the guide rails 33, 34- in vertically spaced relation tothe guide blocks 37, 38 and are connected by a horizontally extendingshaft 42. A pair of supports, indicated generally at 43, are journalledon each of the shafts 39, 42 adjacent the blocks 37, 38 and 46, 41. Thesupports 43 include a generally rectangular body 44 having atransversely extending bore 45 formed therein through which the shafts39, 42 extend. A pair of spaced apart parallel L-shaped links 46, 47extend upwardly from the body 44 and a second pair of spaced apartparallel L-shaped links 48, 49 extend oppositely from the body 44. Theouter end portions of the links 46, 47, 48, 49 are each provided with atransversely extending bore 50.

A pair of spaced apart parallel vertically extending bars 51, 52 havetheir opposite upper and lower ends respectively secured to the links48, 49 by means of pivot pins 53. The bars 51, 52 are arranged intransversely spaced relation and are connected by a horizontallyextending yoke shaft 54.

A pair of spaced apart parallel angle iron uprights, indicated generallyat 55, 56, are positioned to engage between the links 46, 47 at theupper and lower ends thereof and are secured thereto by pivot pins 57.The uprights 55, 56 are each provided with a downwardly and outwardlysloping cam plate 58 secured to the lower ends thereof. The cam plates58 each project inwardly beyond the uprights 55, 56 to provide a hook 59on the lower inner edge of each of the uprights 55, 56.

A pair of vertically spaced parallel transversely extending bars 60extend between and connect the uprights 55, 56, as can be best seen inFIGURE 6. The guide blocks 37, 38, 40, 41 are mounted for verticalsliding movement on the guide rails 33, 34 and with the structuresupported thereon including the uprights 55, 56 form a lifting carriage,indicated generally at 61. The guide rails 35, 36 have an identicallifting carriage 61 mounted thereon in opposed relation to the liftingcarriage 61 mounted on the guide rails 33, 34.

A conveyor including a pair of spaced apart parallel conveyor chains 62is supported in the floor 63 on which the crate stacker is mounted andthe spaced apart parallel chains 62 are arranged intermediate the pairof frame members 21, 22 and the pair of frame members 23, 24 andparallel thereto. The chains 62 extend through the stacker 20 andoutwardly therefrom, both to the front and to the rear thereof. A pit 64is formed in the floor 63 intermediate the upright frame members 21, 22,23, 24 to permit the lower ends of the uprights 55, 56 to be lowered onthe guide rails 33, 34, 35, 36 to a point where the hooks 59 areslightly below the upper plane of the conveyor chains 62. The conveyorchains 62 are of conventional design and form a part of the presentinvention only as the remaining portions of the crate stacker 20 arecombined therewith. The chains 62 are provided for moving the crateswithin the dairy over relatively long distances with the crates arrangedindividually or stacked.

A pair of spaced apart parallel U-shaped brackets 65 are mounted in thepit 64 on opposite sides thereof. A generally horizontal U-shaped stopsupport, generally indicated at 66, has a pair of spaced apart parallellegs 67 connected by a bight 68. The legs 67 and the free ends thereofare pivotally secured to the brackets 65 by pivot pins 69. The legs 67at the ends thereof opposite the brackets 65 are each provided with anoutwardly extending generally horizontal spring pad 70. A coil spring 71is positioned in the bottom of the pit 64 and engages against theunderside of each of the spring pads 70 to normally urge the stopsupport 66 upwardly into contact with the underside of the conveyors 62.A pair of stop plates 72 are secured to the bight 68 in spaced apartparallel upstanding relation adjacent to and intermediate the chains 62.A pilot valve, generally indicated at 73, is supported on each of thestop plates 72 and has the actuator button 74 thereof projecting beyondthe stop plate 72.

An upright pneumatic cylinder 75 has its lower end supported on theframe members 27a, 28a intermediate the opposite ends thereof. Thepneumatic cylinder 75 has a piston rod 76 depending therefrom andarranged for vertical reciprocation when air is supplied to oppositeends of the cylinder 75. A horizontal yoke 77 is pivotally mounted as at77a on the lower end of the piston rod 76 and is provided withoppositely extending stub shafts 78 at opposite ends thereof. Agenerally upright shaft 79 is arranged at each end of the yoke 77 and ispivotally secured thereto by a bearing block 80. The lower ends of theshafts 79 are connected respectively to the shafts 54 by bearing blocks81. Vertical movement of the yoke is effective to vertically move theshafts 79 and therethrough to vertically reciprocate the carriages 61 onthe guide rails 33, 34, 35, 36.

A double-acting hydraulic ram 82 is mounted on each of the shafts 79 andthe pistons 82a of the hydraulic rams 82 are fixedly secured to theshafts 79. A pair of spaced apart parallel support rods 83 are pivotallymounted at their upper ends in bearing blocks 84 carried respectively bythe transverse frame members 25, 26. The lower ends of the rods 83 arepivotally connected to the upper ends of the hydraulic rams 82 by meansof bearing blocks, generally indicated at 85. The rods 83 support thehydraulic rams 82 to maintain them against vertical movement as theshafts 79 are reciprocated vertically therethrough by means of thepneumatic cylinder 75. The hydraulic rams 82 are interconnected by meansof conduits 86 so that the upper end of each of the rams 82 is connectedrespectively to the lower end of the opposite hydraulic ram 82. With thehydraulic rams 82 interconnected, as described, they function as anequalizer and the shafts 79 move equally therethrough, maintaining thecarriages 6 1 in horizontally aligned relation to each other as they aremoved vertically on the guide rails 33, 34, 35 and 36.

In FIGURE 12 a stop release assembly is indicated generally at 87 andconsists of a pair of brackets 88 which extend horizontally inwardlyfrom the blocks 38, 41 adjacent the frame member 24. An upright angleiron member 89 is carried by the inner ends of the brackets 88 andextend substantially thereabove. A lever 90 is pivoted at 91 to theupper end of the angle iron member 89 and is provided with ananti-friction roller 92 in its outer lower edge for engaging the upperedge of the uppermost crate when a sufficient number of crates have beenplaced in the stack. A push rod 93 is secured to the angle iron 89 bymeans of bearings 94 and is arranged for vertically sliding movement.The upper end of the push rod 93 is pivotally connected at 95 to a slot96 in the lever 90 so that upon upward movement of the roller 92 on thelever 90 the push rod 93 will be moved downwardly with respect to theangle iron 89. A coil Spring 97 encompasses the push rod 93 engaging atits lower end one of the bearings 94 and its upper end a pin 98 in thepush rod 93. The spring 97 normally biases the push rod 93 upwardly inthe bearings 94. The lower end of the push rod 93 overlies the springpad 70 closest to the upright frame member 23 and is arranged to pressthe stop support 66 downwardly on downward movement of the carriage 61when the lever 90 engages the upper edge of a crate when the stackbecomes sufliciently high. The stop plates 72 and the pilot valves 73are lowered into the pit 64 when the push rod 93 presses the stopsupport 66 downwardly so that crates supported on the conveyor chains 62may move out of the stacker 20 to be conveyed to the desired location.

In FIGURE 13, a control valve, indicated generally at 99, is illustratedin longitudinal section and comprises a body 100 having a piston typecontrol valve plug 101 mounted for reciprocation therein. Ports 102, 103are arranged in opposite ends of the body 100 for connection to pilotvalves 73 to move the piston plug 101 within the body 100 to control theflow of air to the pneumatic cylinder 75. An air inlet port 104 isconnected to an air pressure regulator R and the outlet ports 105, 106are connected respectively to opposite upper and lower ends of thepneumatic cylinder 75. With the valve plug 101 in the positionillustrated in FIGURE 13, the inlet port 104 is connected to the outletport and an exhaust port 107 is connected to the outlet port 106. Withthe valve plug 101 at its opposite end, the outlet port 106 is connectedwith the inlet port 104 and the outlet port 105 is connected with anexhaust port 108.

A pilot valve 73 is mounted on each of the stop plates 72, as describedabove, and a second pilot valve 73 is secured to each of the guide rails34, 36 for engagement by the carriages 61 at their lowermost position oftravel.

In FIGURE 14 the pilot valve 73 is illustrated in longitudinal sectionand includes a body 109 having a piston type valve plug 110 positionedtherein for reciprocation. A spring 111 normally urges the piston plug110 toward the left end of the body 109, as viewed in FIGURE 14. Theactuator button 74 is connected directly to the piston plug 110 and iseffective to move the piston plug 110 against the tension of the spring111. A pair of convertible inlet and exhaust ports 112, 113 are arrangedon one side of the pilot valve 73 and an outlet port 114 is positionedon the opposite side of the body 109 intermediate the convertible inletand exhaust ports 112, 113.

Referring now to FIGURE 16, the pneumatic circuits for controlling thepneumatic cylinders 75, including the pilot valves 73 and the controlvalve 99, is diagrammatically illustrated. The four pilot valves 73 areseparately indicated by the letters A, B, C and D so that their functionmay be described below. The valve A is mounted on one of the stop plates72 and has an inlet pipe 115 connecting the port 113 to a pneumaticpressure line 116. An exhaust pipe 117 is connected to the port 11 2 andan outlet conduit 118 extends outwardly from the port 114. The pilotvalve B is mounted on the guide rod 34 and has the outlet conduit 118from the valve A extending to the port 112 thereof. An exhaust pipe 119extends from the port 113 and an outlet conduit 120 is secured to theoutlet port 114. The outlet conduit 120 is connected to the port 102 ofthe control valve 99. The connection of the inlet conduit 115 to theport 112 and the outlet conduit 118 to the port 114 in the valve Acreates a normally closed condition so that no flow is establishedthrough the valve A except when the actuator button 74 is depressed,moving the piston plug 110 to the right, as viewed in FIGURE 14. Whenthe button 74 is depressed the piston plug 110 connects the outletconduit 118 to the inlet conduit 115 to permit the passage of airoutwardly through the valve A. The valve B is connected oppositely ofthe valve A to have a normally open condition in which the outletconduit 120 is normally connected to the outlet conduit 118 of the valveA. When the button 74 thereof is depressed, the piston plug 110 blocksthe passage of air from the outlet conduit 118 of the valve A to theoutlet conduit 120 of the valve B. When the button 74 is depressed thepiston plug 110 connects the outlet conduit 120 to the exhaust pipe 119to vent the control valve 99. As can be clearly seen from the above,both the valve A and the valve B must be in open position for air toreach the port 102 of the control valve 99 so as to move the piston 101to the opposite end of the body 100 than that illustrated in FIGURE 13.

The valve C is normally closed and is connected to the inlet conduit 115through its port 113. An outlet conduit 121 connects the port 114 of thevalve C with the port 113 of the valve D. A conduit 122 connects theoutlet port 114 of the valve D with the port 103 of the control valve99. The valve D is normally closed and for air from the supply conduit115 to reach the port 193 of the control valve 99, both the valve C andthe valve D must have the button 74 thereof depressed to open thevalves.

The valves A and C are both moved to open position by contact therewithof a crate 123 moving on the conveyor chains 62. The carriages 61 wouldbe in their lowermost position with the valve B closed and the valve Dopen. With the valves C and D open, pressure fiows through the line 122to the port 193 moving the piston plug 101 to the right, as viewed inFIGURE 13. In this position of the plug 101, air flows from the inletline 124 through the line 125 to the lower end of the cylinder 75 andthe piston rod 76 is moved upwardly. As the piston rod 76 moves upwardlythe yoke 77 and the shafts 79 are raised, pulling upwardly on the shafts54. Initial upward movement of the shafts 54 will raise the bars 51, 52and pivot the supports 43 on the shaft 42, lowering the lifting members55, 56 and moving them inwardly so that the hooks 59 may engage underopposite side edges of the crate 123. Continued lifting movement of thepiston rod 76 will raise the carriages 61 and the crate 123 to the upperlimit of their movement. When the carriages 61 have been raised to theupper limits of their travel, pressure remains on the underside of thepneumatic cylinder 75 to maintain the carriages 61 in their upperposition. A second crate 123 then moves inwardly on the conveyor chains62 and contacts the stops 72 engaging the buttons 74 of the valves A andC, moving them from their normally closed position to open position. Themovement of the carriages 61 away from the valves B and D had permittedthe valve B to return to its normally open position and the valve D toreturn to its normally closed position. As soon as the valve A is openedby the succeeding crate 123 air flows to the port 102 of the controlvalve 99 moving the piston plug 101 to the opposite end tosimultaneously connect the conduit 125 to an exhaust pipe 126 and toconnect the inlet pressure line 124 to the conduit 127 extending to theupper end of the pneumatic cylinder 75. The reversal of the valve 99causes the pneumatic cylinder 75 to operate in a reverse direction andthe piston rod 76 thereof moves downwardly so that the carriages 61place the original crate 123 on top of the second crate 123 and thenmove on downwardly to their original position with the hooks 59positioned below the top level of the chain 62. As soon .as thecarriages 61 have reached their lowermost position, the valve D isopened and the valve B is closed to again reverse the valve plug 101 inthe control valve 99. The vertical reciprocating movement of thecarriages 61 is continued in a like manner until a predetermined numberof crates 123 are stacked one on top of the other to create, forinstance, a stack of five crates 123. When the fifth crate 123 has beenpositioned beneath the stack held in the carriages 61, downward movementof the carriages 61 will cause the lever 99 to engage the upper edge ofthe uppermost crate so as to move the push rod 93 downwardly in aposition to contact the spring pad 79, whereupon the stops '72 aredepressed and the stack of crates 123 is permitted to move out of thestacker 20 on the conveyor chains 62.

It should be understood that the conveyor chains 62 have a relativelysmooth upper surface and the crates 123 may slide thereon whenever thestops 72 are in their raised position, as illustrated in FIGURE 10.

When the stack of crates 123 has been moved out of the crate stacker 20on the conveyor chains 62, the lever disengages from the top crate 123and the spring 97 and the spring 71 return the push rod 93 and the stopsupport 66 to their raised positions for engagement of the next crate123 moving on the conveyor chains 62.

It can be seen from the description above that crates moving inindividual successive positions on the conveyor chains 62 will beindividually stopped in position for the carriages 61 to raise themabove the conveyor chains 62, permitting the next successive crate 123to be moved into position at the bottom of the stack.

Having thus described the preferred embodiment of the invention, itshould be understood that numerous structural modifications andadaptations may be resorted to without departing from the scope of theappended claims.

What is claimed is:

1. A crate stacker comprising an upright frame, a vertically disposedfluid pressure cylinder mounted on the upper end of said frame, areciprocable piston rod in said fluid pressure cylinder extendingtherefrom into said frame, a transverse member pivotally securedintermediate its ends to the free end of said piston rod, verticaloppositely disposed guide means on said frame adjacent the lower endportion thereof, lift carriages operatively connected to each of saidguide means and movable relative thereto, a pair of elongated rods eachhaving one of their ends secured to the ends of said transverse memberand each pivotally secured at their other ends to said lift carriages,each of said elongated rods extending through one of a pair of hydrauliccylinders mounted in said frame, pistons fixed to said rods and residingin said hydraulic cylinders, each of said hydraulic cylinders havingtheir opposite ends in communication to equalize move- 7 ment of saidlifting carriages, crate engaging means on said lift carriages movablefrom an inoperative position to a crate engaging position in response tomovement of said pair of elongated rods, and means to position crates insaid frame to be engaged by the crate engaging means on said liftcarriages.

2. A crate stacked as defined in claim 1 wherein said lift carriagesinclude pairs of vertically extending bars secured together intermediatetheir ends in spaced parallel relation, the lower ends of each of saidpairs of bars having interconnected supports pivotally secured thereto,the upper ends of each of said pairs of bars having interconnectedsupports pivotally secured thereto and said crate engaging meanspivotally secured to said support.

3. A crate stacker as defined in claim 1 which includes a control valvehaving a fluid inlet port and fluid outlet ports in communication withopposite ends of said fluid pressure cylinder, pilot valves having fluidinlet ports and fluid outlet ports in communication with said controlvalve, certain of said pilot valves actuated by a crate positioned insaid frame, other of said pilot valves actuated by said lift carriagesto alternately direct a flow of fluid to opposite ends of said fluidpressure cylinder.

4. A crate stacker as defined in claim 1 wherein said means to positioncrates in said frame includes a crate carrying conveyor extendingtherethrough, a pivoted stop support having stop means thereon, saidstop means normally in crate engaging position in the path of travelthereof to position crates carried by said conveyor for engagement bysaid crate engaging means on said lift 30 carriages.

5. A crate stacker as defined in claim 4 which further includes meansmounted on and movable with one of said lift carriages and engageablewith a stacked crate, movement of said means effecting pivotal movementof said stop support to move the stop means carried thereby from thepath of travel of crates carried by said conveyor whereby a stack ofcrates within said frame can be moved therefrom.

6. A crate stacker as defined in claim 5 wherein said means compriseshorizontal brackets each secured at one end to said lifting carriage, anupright member secured to the other ends of said brackets, a leverpivotally secured intermediate its ends to said upright member, a rollersecured to one end of said lever and engageable with the uppermost of astack of crates, a vertically movable push rod pivotally secured to theother end of said lever, the free end of said push rod in overlyingrelation to said stop support.

References Cited in the file of this patent UNITED STATES PATENTS1,724,304 Newnam Aug. 13, 1924 2,028,410 Rapisarda Jan. 31, 19362,283,447 MacMillin et a1 May 19, 1942 2,609,111 Daves et a1 Sept. 2,1952 2,687,813 Verrinder et al Aug. 31, 1954 2,795,346 Farmer June 11,1957 FOREIGN PATENTS 731,496 Great Britain June 8, 1955

